Water

Rather than running an invisible pipe under the street, strategies are used to mimic the patterns of natural water systems by capturing and slowing water close to where it falls. These strategies not only reduce erosion, replenish groundwater and keep water temperatures low, they also create habitat, make special places and save money. In some cases, developable land is even increased by trading stormwater ponds for swales and trenches that are more flexibly located.

Green roofs clean airborne pollutants from rain, and reduce the rate and quantity of stormwater runoff. A building with a green roof requires significantly less conventional stormwater detention and cleansing facilities, and benefits downstream systems by reducing the volume. Rainwater is absorbed by the soil, taken up by plants and returned to the atmosphere. It is common to decrease annual runoff -- and stormwater detention facilities -- by